The wireless communication system has been developed in a variety of manners in recent years. As for a service, for example, browse of websites and VoIP (Voice over IP) may be included. In addition, as for a hardware, multimode terminals have been popularly used, which have a plurality of wireless interfaces (hereinafter, an interface is appropriately abbreviated to an IF) corresponding to different wireless communication networks such as, for example, a combination of a CDMA (Code Division Multiple Access) network and a wireless LAN (Local Area Network).
On the other hand, the wireless communication system, for normal connection services except for a leased circuit connection service, generally employs a best effort type. The best effort type is a type of a communication system which does not guarantee quality of service although making an effort to maintain a good communication service. For example, if there are only a small number of wireless communication terminals connecting to an access point (hereinafter, appropriately abbreviated to AP) which is a base station, a sufficient bandwidth is assigned to each wireless communication terminal. However, the more the wireless communication terminals connect to the AP, the narrower bandwidth is assigned to each wireless communication terminal, which makes a communication speed slowed down. Additionally, if a communication amount reaches the trunk capacity of the AP, the wireless communication system rejects a connection of a new wireless communication terminal.
Accordingly, it is concerned for the communication system of the best effort type that, in proportion to the increase in users in the recent years, the bandwidth assignable to each wireless communication terminal becomes narrower and thus it is often occurred that the communication speed slows down or connection is rejected.
In order to solve such problems, there is known a communication system which, for example, prioritizes wireless communication terminals in order to control connections based on the priority (For example, see Patent Document 1). In this communication system, if a connection exceeding throughput is requested, a gatekeeper refers to the priorities of the wireless communication terminals in communication and the priority of the wireless communication terminal requesting the connection and, within a range maintaining a total communication amount equal to or less than the throughput, sequentially selects wireless communication terminals with higher priorities to perform communications. Then, it is controlled such that the wireless communication terminals selected connect in a conventional manner, whereas wireless communication terminals unselected search for indirect routes to find another access point. Accordingly, the wireless communication terminals with higher priorities can achieve a bandwidth requested by a user. In addition, if there is an indirect route, more wireless communication terminals than ever before can perform communication.
In addition, there is known another wireless communication system for controlling connections of multimode terminals having a plurality of wireless IFs, which selects another wireless IF to make the wireless communication terminal perform handoff when a communication environment of the wireless IF used by the wireless communication terminal is deteriorated (for example, see Patent Document 1). In this wireless communication system, the server selects a wireless IF which can be used by the wireless communication terminal based on terminal management information and network management information in response to a request for handoff from the wireless communication terminal, and notifies the wireless communication terminal of the wireless IF. Thereby, the wireless communication terminal performs control for handoff to the wireless IF in such notification. Therefore, according to this wireless communication system, if wireless communication terminals in the network performs handoff actively, the number of terminals connected to one AP is reduced, which increases the possibility that each wireless communication terminal can obtain a desired bandwidth.